KR102183596B1 - Ground-fault detector in commercial AC station with ground potential transformer at PV-station and operating system thereof - Google Patents

Abstract

The present invention relates to a DC-circuit ground-fault detection device for a circuit-integrated neutral grounding transformer in a photovoltaic power generation system and an operating system therefor, capable of preventing occurrence of fire caused by thermal storage. According to the present invention, the operating system for the DC-circuit ground-fault detection device for the circuit-integrated neutral grounding transformer in the photovoltaic power generation system includes: the DC-circuit ground-fault detection device for the circuit-integrated neutral grounding transformer in the photovoltaic power generation system; a system operation control unit; a short-range multiple wireless communication unit; an access prevention device unit; and a smart mobile unit.

Description

Ground-fault detector in commercial AC station with ground potential transformer at PV-station and operating system thereof, for photovoltaic power generation system converter-integrated neutral point ground transformer

The present invention relates to the field of photovoltaic power generation system (PV-station) technology, by integrating DC and AC converters using a ground potential transfomer (GPT), and distinguishing between DC and AC converters. It relates to a device that detects, and more specifically, produces direct current on the direct current side of the photovoltaic power generation system (hereinafter referred to as'direct current converter') and converts it to a frequency of 60 Hz by a non-insulated inverter to the alternating current side (hereinafter, It is referred to as'AC converter'.) It integrates the neutral point of DC and AC while supplying it in connection with the commercial system, but separates the DC line and AC line so that they do not interfere with each other (DC Galvanic) and monitors the image voltage of the AC line. A photovoltaic power generation system that detects the occurrence of a ground fault in the furnace and prevents burnout and fire accidents in the neutral point grounding transformer. The present invention relates to a DC converter ground fault detection device for a neutral point grounding transformer.

Solar power generation system (PV-station) that generates power using solar power generates (produces) DC power by converting sunlight into electric signals in a DC converter, converts DC into AC in an inverter, and smoothing and smoothing in an AC converter. It consists of a configuration that connects and supplies a commercial power system (commercial system) through frequency stabilization.

The earth has finite resources such as petroleum and coal, and if such finite resources are used, the energy use efficiency is relatively high, but there is a problem of warming the earth by generating a lot of carbon dioxide, etc., and wind and sunlight as infinite resources. In the case of generating energy using these resources, there is a problem of relatively low efficiency with the current technology, but there is an advantage of being very eco-friendly as new renewable energy because carbon dioxide is very low.

Solar power generation system (PV-station) is a configuration that increases voltage and current to a designed capacity because a number of modules in which a number of solar cell units are connected in series and modules connected in parallel are repeatedly connected in the required quantity according to the corresponding design. Area is required, and the connection part or string that connects multiple solar modules is exposed, so as time passes, accidents such as poor contact or short-circuit with other parts or ground fault occur. Not only can it cause problems, but it can also lead to personal accidents, and it can cause problems such as lowering the power generation efficiency, shortening the life of connected devices, and causing a fire.

Due to the nature of the photovoltaic power generation system, it cannot generate electricity at night without sunlight, when there is a lot of clouds, or when it is snowy or rainy, and it requires a large installation area, but it does not emit carbon dioxide. Thanks to this, the power generation capacity and installation area per unit area are gradually increasing. On the other hand, the generated DC power can be converted into AC power and used not only by itself, but also supplied to a commercial system.

The commercial system is supplied after the voltage of the DC power generated by the solar cell module of the solar power generation system is boosted by the booster circuit and converted into AC power of the same frequency as the commercial system by the inverter circuit.

The photovoltaic power generation system must be equipped with a detection circuit device (ground fault detection device) that detects the occurrence of a ground fault in a DC line including a solar cell and an AC line connected to a commercial system. If an appropriate response is not promptly performed as soon as a ground fault occurs, the device connected to the commercial system is stopped or damaged, and it causes great damage to the booster circuit and inverter for power conversion.

Therefore, the PV-station needs to develop a technology that detects the occurrence of a ground fault quickly, accurately and stably.

As a technology that solves the problems and necessity of the prior art, it is based on Korean Patent Registration No. 10-1090263 (2011. 11. 30.)'Ground fault detection circuit device and ground fault detection method with direct current wire of solar power generation system'. There is this.

1 is a functional configuration diagram of a DC converter ground fault detection device according to an embodiment of the prior art.

Hereinafter, referring to the accompanying drawings, the conventional technique will be described in detail, including a solar cell module 1, a voltage divider resistance circuit unit 2, a voltage sensing unit 3, a control unit 4, an algorithm, and a power converter 11 It is a configuration.

The DC power generated from the DC converter including the solar cell module 1 is converted into AC power in the power converter 11 and supplied to the commercial system via the AC converter.

The voltage dividing resistance circuit unit 2 divides the voltage generated by the solar cell module 1 using series-connected resistors R1 and R2, and the voltage sensing unit 3 detects each resistance of R1 and R2 and the total resistance connected in series, respectively. It detects the voltage, analyzes the voltage detected by the control unit 4 including the algorithm, and estimates whether a ground fault has occurred in the DC converter and, if it occurs, at which location it is issued.

The prior art has the advantage of detecting whether a ground fault has occurred in the solar cell module 1 and detecting the approximate location of the solar cell string where the ground fault has occurred, but there is a problem in that it cannot detect the ground fault of an AC converter. There is a problem in that an additional device for detecting a ground fault in the furnace must be additionally provided, and the solar cell string still suffers from problems such as a decrease in the accuracy of estimating the location of a ground fault due to a change in the contact resistance of each connection point over time. Remains.

Therefore, the occurrence of a ground fault between the DC and AC lines of the PV-station is detected at the same time by using a neutral grounding transformer (neutral grounding transformer), and the DC and AC lines are insulated and do not interfere with each other. It is separated without the need to develop technologies such as preventing burnout or fire accidents in the neutral ground transformer.

Republic of Korea Patent Registration No. 10-1090263 (November 30, 2011),'Ground fault detection circuit device and ground fault detection method with direct current wire of solar power generation system' Republic of Korea Patent Registration No. 10-1695672 (announced on Jan. 23, 2017),'Current cut-off trip method for detecting ground fault area of multi-solar cell array and maintaining solar power generation, ground fault area detection and solar power generation maintenance system for this ' Korean Patent Registration No. 10-1699500 (announced on February 13, 2017),'Solar power generation system with power storage function with ground fault detection function' Korean Patent Registration No. 10-0973549 (Announcement on Aug. 2, 2010),'Method and device for limiting image current'

The present invention, conceived to solve the problems and necessity of the prior art as described above, generates direct current power in a solar power generation system (PV-station) and converts it into AC power of a frequency of 60 Hz by a non-insulated inverter to be used in a commercial system. When a ground fault occurs while connecting and supplying, a neutral point grounding transformer is used to detect and analyze the image voltage from the AC line to quickly detect the ground fault of the DC line with a simple configuration, thus preventing burnout and fire accidents of the neutral point grounding transformer. Its purpose is to provide a DC converter ground fault detection device for a photovoltaic system converter integrated neutral point grounding transformer.

In addition, the present invention uses one neutral ground transformer and monitors the insulation of the DC line by detecting the image voltage of the AC line, and separates the AC line and the DC line of a non-insulated inverter that do not affect or interfere with each other ( The purpose is to provide a DC converter ground fault detection device for a solar power generation system converter that operates in the DC Galvanic) state, prevents safety accidents such as electric shock, and prevents the occurrence of fire due to heat storage of the neutral ground transformer. .

On the other hand, the present invention prevents a fire accident due to power generation stop damage due to malfunction of a ground fault detection device of a solar power generation system and burnout of a neutral point grounding transformer, and a DC converter by separating a DC converter and an AC converter that does not affect each other. Its purpose is to provide a DC converter ground fault detection device for a photovoltaic power generation system converter integrated neutral point transformer that prevents the effects of ground faults such as solar power modules and string wiring from spreading to the AC converter.

The DC converter ground fault detection device for a photovoltaic power generation system converter-integrated neutral point grounding transformer of the present invention conceived to achieve the above object is 3 of 60 Hz by the inverter 920 DC power generated by the solar module 910 In the DC converter ground fault detection device for a photovoltaic power generation system converter integrated neutral ground transformer including a neutral ground transformer 930 that receives AC power converted into a phase and outputted through a primary winding 931, the primary winding Further comprising a DC line ground fault detection unit 970 that is interposed between the neutral point of 931 and the ground point and detects the occurrence of a ground fault of the DC line by detecting the image voltage, the DC line ground fault detection unit 970 A capacitor 971 connected in series between the neutral point and the ground point of the primary winding 931; A first resistor 972 having one end connected to the neutral point of the primary winding 931; A second resistor 973 having one end connected to the other end of the first resistor 972 and the other end connected to the ground point; A bridge diode part 974 connecting an input terminal to one end of the second resistor and the other end of the second resistor; When it is connected to the output terminal of the bridge diode unit 974 and detects the level of the video voltage distributed by the second resistor 973 and analyzes the level above the set voltage, it is determined that a ground fault has occurred in the DC line and an alarm message is displayed. An image voltage current detector 960 to output; It may include.

The capacitor 971 is made of 92 microfarads, the first resistor 972 is made of 50 kilohms, the second resistor 973 is made of 5 kilohms, and the first resistor 972 And the second resistor 973 may be connected in parallel to the capacitor 971 while being connected in series.

The DC converter ground fault detection device operating system for a photovoltaic power generation system converter-integrated neutral point grounding transformer of the present invention devised to achieve the above object is the direct current of the DC converter ground fault detection device for a photovoltaic power generation system converter-integrated neutral-point grounding transformer. An image voltage current detection unit 960 for detecting occurrence of a ground fault in the converter; A system operation control unit 1100 that connects to the image voltage and current detection unit 960, controls and monitors the operation of the entire system, and controls and monitors an alarm message to be output when a ground fault occurs in a DC line; Short-distance for simultaneous access to a designated counterpart by activating multiple wireless communication paths of Wi-Fi method, Bluetooth method, and infrared method by the corresponding control signal of the system operation control unit 1100 and transmitting or receiving a communication signal notifying the occurrence of a ground fault. Multiple wireless communication unit 1200; An access prevention device unit 1300 that is installed around a ground fault in response to a corresponding control signal from the system operation control unit 1100 and visually displays a guide message indicating that the ground fault has occurred; A smart mobile unit 1500 for receiving and outputting a communication signal notifying the occurrence of a ground fault and simultaneously wirelessly accessing the short-range multiple wireless communication unit 1200 and multiple wireless communication paths; It may include.

A multi-wireless communication module unit 1400 for transmitting the warning message of the occurrence of a ground fault according to the corresponding control signal of the system operation control unit 1100 through three communication paths according to a CDMA method, a TRS method, and an FM SSB method; A multi-public communication network unit 1600 wirelessly connecting to the multi-wireless communication module unit 1400 and transmitting an alarm message signal of an occurrence of a ground fault to a designated counterpart connected by switching; An integrated management server (1700) connecting to the multi-public communication network unit (1600), recording and storing an alarm message signal of a ground fault occurrence in an allocated area, and outputting by searching; It may further include.

The present invention of the above-described configuration generates DC power in a photovoltaic power generation system (PV-station), converts it to a frequency of 60 Hz through a non-insulated inverter, and detects the image voltage of an AC converter connected to a commercial AC system. Since the occurrence of a ground fault in the converter is quickly detected with a simple configuration, it has the advantage of preventing burnout and fire accidents of the neutral point transformer.

In addition, it monitors the insulation of the DC line by detecting and analyzing the image voltage of the AC line using only one neutral ground transformer, and the AC line and the DC line of the non-insulated inverter operate in a DC galvanic state without mutual influence or interference. It has the advantage of preventing safety accidents such as electric shock and preventing fires due to heat storage.

On the other hand, in the PV-station, power generation stop damage due to malfunction of the ground fault breaker and fire accident due to burnout of the neutral point transformer are prevented, and the DC converter is separated by the DC converter and the AC converter. There is an advantage in that the effect of the ground fault does not spread to the AC circuit.

1 is a functional configuration diagram of a DC converter ground fault detection device according to an embodiment of the prior art,
2 is a configuration diagram of a DC converter ground fault detection device for a solar power generation system converter integrated neutral point grounding transformer according to an embodiment of the present invention,
3 is a diagram illustrating a flow path of a ground fault current in a DC converter caused by a ground fault when a neutral ground transformer is used according to an embodiment of the present invention;
4 is a configuration diagram of a DC converter ground fault detection device for a solar power generation system converter-integrated neutral point grounding transformer according to an improved embodiment of the present invention;
5 is a detailed functional configuration diagram of a neutral point integrated DC converter ground fault detection unit according to an improved embodiment of the present invention;
6 is a functional configuration diagram of a DC converter ground fault detection reporting system for a solar power generation system converter-integrated neutral point grounding transformer according to another improved embodiment of the present invention;
And
7 is a detailed configuration diagram illustrating a device for preventing access of a DC converter ground fault detection notification system for a photovoltaic power generation system converter-integrated neutral point grounding transformer according to another improved embodiment of the present invention.

Since the present invention may apply various transformations and may have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all conversions, equivalents, or substitutes included in the spirit and scope of the present invention. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

2 is a configuration diagram of a DC converter ground fault detection device for a photovoltaic power generation system converter-integrated neutral point grounding transformer according to an embodiment of the present invention, and FIG. 3 is a neutral point grounding transformer according to an embodiment of the present invention. Is a diagram illustrating the flow path of the ground fault current in the DC converter due to the occurrence of a ground fault, and FIG. 4 is a diagram illustrating a DC converter ground fault detection device for a solar power generation system converter-integrated neutral point grounding transformer according to an improved embodiment of the present invention. FIG. 5 is a detailed functional configuration diagram of a neutral point integrated DC converter ground fault detection unit according to an improved embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to all the accompanying drawings. The ground fault detection device 800 using a neutral ground transformer includes a solar module 810, an inverter 820, a neutral ground transformer 830, The configuration includes a current limiting resistor 840, a circuit breaker 850, and an image voltage current detection unit 860.

The solar module 810 is a type of semiconductor device that receives a solar signal, converts it into a direct current electrical signal, and outputs it.

Since the DC voltage and current level output by one solar cell is determined by the characteristics of the semiconductor device, the voltage is increased by connecting a plurality of solar cells in series, and the current is increased by reconnecting a number of modules connected in series in parallel again. A solar module 810 configured to output a desired constant level of voltage and current by repeating the process will be referred to as a solar module 810. Since the voltage and current output from the unit solar cell are very common and well known, further detailed description will be omitted, but one solar cell as the minimum unit corresponds to a semiconductor device.

Since the voltage and current levels output by the unit solar module 810 are limited, if a higher level of voltage and current is required, repeat as described above and connect the plurality of solar modules 810 in parallel again and again as above. Since the series connection is repeated, high current and high voltage DC are generated and output. In the following description, a state configured to generate a voltage and a current of a finally required capacity will be described and understood as the solar module 810.

On the other hand, in general, the level of the DC voltage output from a solar power plant is known to be in the range of 300 volts (V) to 1200 volts, and it is natural that the level can be increased or decreased depending on the development of technology and needs, etc. The process of connecting multiple solar cells or solar modules in series and connecting the serially connected units in parallel is repeated. The power generated and output from the solar module 810 is direct current (DC) power.

The inverter 820 is a component that inputs direct current (DC) power, converts it into 3-phase alternating current (AC) power, and outputs it.

The inverter 820 receives DC power (power) that the solar module 810 generates and outputs by receiving a solar signal, converts it into 3-phase AC power, and outputs it, but converts it to a frequency of 60 Hz according to the domestic situation. do. At this time, the inverter 820 is provided with a sufficient internal voltage to operate by receiving the high voltage and current that the solar module 810 generates and outputs. In order to supply it to the commercial system, the inverter 820 needs to be converted and output to 3-phase AC at a frequency of 60 Hz. It will be described and understood as using the inverter 820.

Up to the input terminal of the inverter 820 is included in the DC converter, and the output terminal is included in the AC converter.

The neutral point grounding transformer 830 receives the three-phase AC power converted and output by the inverter 820 into the primary winding 831, and the voltage level is converted and output according to the winding ratio, so that a ground fault can be detected. It is a configuration provided to each of the secondary winding 832 and the tertiary winding 833, and since the number of turns of the secondary winding 832 and the number of turns of the tertiary winding 833 are the same, the secondary winding 832 and 3 The alternating current voltage output to each of the secondary windings 833 is the same voltage level and is a three-phase AC power source.

The current limiting resistor 840 uses an abbreviation of CLR (current limit resistance), and the current flowing through the third winding 833 in a state in which the windings constituting each phase of the third winding 833 are connected directly The voltage is detected and applied to the image voltage current detector 860.

The circuit breaker 850 is configured to block each of the three-phase converters by inputting the corresponding control signal from the image voltage current detection unit 860.

The image voltage current detection unit 860 receives voltage and current detected at both ends of each winding constituting each phase of the secondary winding 832, and also receives the voltage and current detected at both ends of each of the windings of the secondary winding 832. When it is determined that a ground fault has occurred by detecting and analyzing the image voltage and the image current while receiving the flowing voltage and current, the corresponding control signal is output to the circuit breaker 850 to cut off the connection of each of the three phases or the entire connection. do.

The AC converter is equipped with a ground fault detection and blocking device to prevent the occurrence of electric shock and fire due to a ground fault, and the ground fault is a neutral point grounding transformer or a ground potential transfomer (GPT) (830). ) By connecting in an open delta (Δ) method, the image voltage or image residual voltage (hereinafter referred to as'image voltage') is checked, so that the occurrence of a ground fault is detected and the state of the ground fault (failure, failure) is When detected, it is configured to block the corresponding converter in order to prevent safety accidents due to electric shock, etc., and to prevent the occurrence of fire and burnout.

The neutral point grounding transformer (GPT) is equipped with three coils for the three phases of R, S, and T in the primary coil, and three coils for each corresponding three phase on the secondary and tertiary sides. Each of the coils is provided, and each of the three-phase coils is wound at the ratio of the primary side coil: the secondary side coil: the third side coil = 1: n: n by the turns ratio, and the three-phase coil on the primary side and the secondary side The three-phase coil of the side is connected in parallel with the ground point to common ground, and the third coil is connected in series, and the neutral point of the last connected phase coil is connected to the ground.

On the other hand, the DC converter voltage of the PV-station is in a trend of rapidly increasing from 300 volts (V) to 1,200 volts (V), and a direct current converter including a solar power generation (solar cell) module. There is an urgent need to develop a technology that monitors the insulation state of the device to detect and alarm faults such as ground faults.

Solar photovoltaic (solar cell) modules are very common to be installed on the roof or outdoors of buildings without tall obstacles so that they receive a lot of direct sunlight from the sun, so they are directly exposed to the external environment with a relatively high density of lightning. In general, the string wiring by the battery module and the photoelectric conversion device (solar cell) module, which is a semiconductor component, have a very high risk of damage and leakage due to the occurrence of a lightning surge.

Referring to the accompanying Figures 2 and 3 in detail, when a ground fault occurs in a PV-station, it is opened from the third winding 833 of the neutral ground transformer 830. -Detects the image voltage by detecting the resistance drop voltage (voltage drop due to the resistance component) on the delta side, and when the detected image voltage is judged to be above a certain reference value, the circuit breaker 850 is driven to block the AC line. Device configuration.

A fuse (F) to prevent burnout of the neutral ground transformer (GPT) 830 is installed in the primary, secondary, and tertiary windings 831, 832, and 833, respectively, and a current limiting resistor that limits the ground fault current. The neutral point of the tertiary winding 833 on which the (CLR) 840 is installed is commonly grounded.

The non-isolated inverter 820 must be configured as a non-grounding array in order to completely separate or block the fault current (ground fault current) from flowing to the main circuit (AC converter) connected to the commercial system when a fault (fault) such as a ground fault occurs.

The non-isolated inverter 820 has a configuration without only one (1) simple insulation between the main circuit (AC converter) and the solar circuit (DC converter) connected to the commercial power source (inverter circuit, switching circuit).

When a ground fault (fault, breakdown) occurs in a DC system or DC converter including the non-isolated inverter 820 and the solar (solar cell) module 810, the DC ground fault current (Ig) is converted into a non-isolated inverter. Since it flows in the state of excess current (overcurrent, leakage current) corresponding to the number multiple of the rated current through the primary winding 831 of the neutral point grounding transformer (GPT) 830 through 820, the neutral point grounding transformer (GPT) ( 830) may cause fire, damage to property, safety accidents due to electric leakage, and personal and livestock accidents. The magnitude of the overcurrent due to the ground fault is the same as the maximum short-circuit current (Igg) that the solar (solar-cell) module 810 can supply. On the other hand, ground current, overcurrent, and leakage current have the same meaning and will be used selectively appropriate to the context.

Problems expected as a phenomenon caused by the occurrence of a ground fault are as follows.

first ; The leakage current or ground fault current (overcurrent, Ig) flowing through the primary winding 831 of the neutral point ground transformer (GPT) 830 through the non-insulated inverter 820 due to a ground fault is the protective fuse of the neutral point ground transformer 830 (F) is blown (melted and cut), and as a result, an image voltage that can be judged as a ground fault is detected in the AC line, and the power supply is cut off due to the operation of the circuit breaker 850 included in the corresponding safety device, and solar power generation. A situation arises in which it is stopped.

second ; When overcurrent (Ig) due to a ground fault passes through the non-isolated inverter 820 and flows through the primary winding 831 of the neutral grounding transformer 830, the magnitude of the overcurrent Ig is in the normal state of the neutral grounding transformer 830 In case the rated current is exceeded, but is less than the conventional non-fusing current (I _nf ), which is insufficient to blow the corresponding protection fuse (F), the transformer 830 for neutral point grounding is stored by the corresponding overcurrent (Ig). A phenomenon occurs, and as a result, a fire occurs and burns out.

When a ground fault occurs in a DC or AC line, the ground fault current (Ig) is calculated according to the value of the internal resistance (R) by the tertiary winding (833) of the neutral point grounding transformer (830). ) Is detected, and the image voltage detected by the voltage drop occurring at both ends of the current limiting resistor 840 is analyzed by the image voltage current detector 860 to determine whether a ground fault has occurred, and necessary control such as blocking the corresponding converter Will do.

[Calculation 1]

Ig = (3 * E) / n** (R/3)

E = phase voltage

n = turn ratio of the third winding corresponding to the primary winding

R = internal resistance value of the third winding

This configuration has the advantage of detecting the occurrence of a ground fault in a DC converter or an AC converter, but it takes a lot of time and is not economical to go through a complicated process to distinguish whether a ground fault has occurred in a DC converter or an AC converter. Therefore, there is a need to develop a DC converter ground fault detection device for an improved solar power generation system converter integrated neutral point grounding transformer. In addition, in the case of detecting the ground fault current generated in each of the DC converter and the AC converter separately, since the DC converter and the AC converter must have respective detection functions, the device configuration becomes complicated and large, resulting in a high cost.

Therefore, an improved technology was needed to detect a ground fault by using a single neutral grounding transformer and integrating a DC converter and an AC converter, but distinguishing whether a ground fault occurred in a DC or AC converter. It will be described with reference to the drawings.

The improved technical configuration will be described mainly with reference to FIGS. 4 and 5, but will be described in detail with reference to all the accompanying drawings. The improved solar power generation system converter integrated neutral point grounding transformer DC converter ground fault detection device 900 is a solar module ( 910), an inverter 920, a neutral point grounding transformer 930, a current limiting resistor 940, a circuit breaker 950, an image voltage current detection unit 960, and a DC line ground fault detection unit 970.

The DC converter ground fault detection device 900 for an improved solar power generation system converter-integrated neutral point transformer is an AC power output by converting the DC power generated by the solar module 910 into three phases of 60 Hz by the inverter 920 In the DC converter ground fault detection device for a photovoltaic power generation system converter-integrated neutral point grounding transformer including a neutral point grounding transformer 930 that is input to the primary winding 931, between the neutral point and the grounding point of the primary winding 931 Further comprising a DC line ground fault detection unit 970 that is connected to the intervening and detects the occurrence of a ground fault of the DC line by detecting the image voltage, the DC line ground fault detection unit 970 of the primary winding 931 A capacitor 971 connected in series between the neutral point and the ground point; A first resistor 972 having one end connected to the neutral point of the primary winding 931; A second resistor 973 having one end connected to the other end of the first resistor 972 and the other end connected to the ground point; A bridge diode part 974 connecting an input terminal to one end of the second resistor and the other end of the second resistor; When it is connected to the output terminal of the bridge diode unit 974 and detects the level of the video voltage distributed by the second resistor 973 and analyzes the level above the set voltage, it is determined that a ground fault has occurred in the DC line and an alarm message is displayed. It is a configuration including a; image voltage and current detection unit 960 to output. Meanwhile, the capacitor 971 is made of 92 microwaves, the first resistor 972 is made of 50 kilohms, the second resistor 973 is made of 5 kilohms, and the first resistor ( 972 and the second resistor 973 are connected in series while being connected in parallel to the capacitor 971.

The solar module 910 has the same configuration and operation as the solar module 810 described in FIGS. 2 and 3, and the inverter 920 has the same configuration and operation as the inverter 820, and a neutral point grounding transformer ( 930 has a primary winding 931, a secondary winding 932, and a third winding 933, has the same configuration and function as the neutral point grounding transformer 830, and the current limiting resistor 940 is the same. The same configuration and operation as the current limiting resistor 840, the circuit breaker 950 is the same configuration and operation as the circuit breaker 850, and the image voltage current detection unit 960 is the same as the image voltage current detection unit ( Since the configuration and operation are the same as those of 860), redundant descriptions will be omitted for easy and simple description and understanding.

Therefore, focusing on the DC converter ground fault detection unit 970, which is provided only in the DC converter ground fault detection device 900 for the improved solar power generation system converter-integrated neutral point grounding transformer, and includes the important technical idea of the improved invention. Focused on the description, but only when necessary, a solar module 910, an inverter 920, a neutral point grounding transformer 930, a current limiting resistor 940, a circuit breaker 950, and an image voltage and current detection unit 960 will be added. do.

The DC line ground fault detection unit 970 is installed between the neutral point and the ground of the primary winding 931 of the neutral point grounding transformer 930 corresponding to the AC line, and the AC line is separated by the DC line and the AC line. It is configured to detect a ground fault of a DC converter.

The DC line ground fault detection unit 970 includes capacitors (C, 971), first resistors (R1, 972), second resistors (R2, 973), and a bridge diode unit 974, but the image voltage current detection unit Since it is connected to 960, a diagram is shown and described as a configuration including the image voltage current detection unit 960.

The capacitor 971 is connected in series between the neutral point and the ground point of the primary winding 931. In general, the condenser (C) is well known for its configuration to pass alternating current and block the passage of direct current, so further detailed description thereof will be omitted. The condenser 971 is very preferable because it is suitable for frequency characteristics to be composed of 92 microwaves (uF) according to an embodiment.

The first resistor 972 is 50 kiohms (KΩ) as an example, and one end is connected to the neutral point of the primary winding 931 and the other end is connected to one end of the second resistor 973.

The second resistor 973 is 5 kiohms (KΩ) as an example, and one end is connected to the other end of the first resistor 972 and the other end is connected to a ground point.

That is, the first resistor (R1, 972) and the second resistor (R2, 973) are connected in parallel with the capacitor 971 in a series connected state, and between the neutral point and the ground point of the primary winding 931 Connected in series.

Since the bridge diode unit 974 is a general configuration that outputs a DC signal as it is when it is input, and converts and outputs a DC component by full-wave rectification when an AC signal is input, a detailed description will be omitted.

The bridge diode unit 974 connects the input terminal to one end and the other end of the second resistors R2 and 973 and receives the voltage distributed by the second resistors R2 and 973 through the input terminal for onion rectification (full-wave rectification). It is configured to output to the output terminal and outputs the full-wave rectified (positive wave rectified) DC signal to the output terminal when the AC component is included in the input voltage input to the input terminal.

The image voltage current detection unit 960 is connected to the output terminal of the bridge diode unit 974 and detects the voltage level input from the output terminal of the bridge diode unit 974 and is recorded and set or analyzed as a voltage higher than the specified level. It is the composition that judges that a ground fault has occurred in. When the video voltage current detection unit 960 determines that a ground fault has occurred in the DC converter, it is very possible to include a function of outputting a corresponding warning or alarm message signal, as well as a number of other functions. Of course.

The DC line ground fault detection unit 970 is a device that separates the AC line and the DC line (DC Galvanic). Since the DC line ground fault detection unit 970 is located on the AC line, the primary winding 931 is normally operated. Since the AC signal flowing through the capacitor 971 flows to the ground, a voltage drop does not occur in the second resistors R2 and 973, so that the image voltage current detection unit 960 cannot detect the voltage.

That is, in the case of normal operation in which a ground fault does not occur, the DC line is separated from the AC line so that the DC line is floating, so that the DC voltage due to the voltage drop is not generated in the second resistors R2 and 973.

On the other hand, when a ground fault occurs in an arbitrary phase (phase) of the DC converter, the ground fault current Ig passes through the corresponding switching circuit by the non-insulated inverter 920 and forms a closed circuit with the solar module 910 It flows through the corresponding neutral point of the DC line ground fault detection unit 970 and the neutral point grounding transformer 930.

At this time, a voltage drop due to the resistance value of the second resistors R2 and 973 provided in the DC line ground fault detection unit 970 is generated and output as an image voltage, and an image generated or output at both ends of the second resistor 973 The voltage is detected by the image voltage current detection unit 960, generates a necessary alarm signal, and controls and monitors the necessary corrective action by notifying a designated counterpart such as a designated manager or operator or an integrated management server. Meanwhile, the voltage drop or image voltage generated at both ends of the second resistors R2 and 973 is calculated as in Equation 2 below.

[Calculation 2]

E * (R2 / (R1 + R2))

E = voltage developed by solar module

R1 = 50 kilohms of first resistance in series

R2 = 5 kilohm second resistor in series

Since the image voltage current detection unit 960 analyzes the voltage levels detected at both ends of the second resistor 973, it determines whether a ground fault has occurred, and when it is determined that a ground fault has occurred, generates a corresponding alarm signal and notifies the designated counterpart. To control and monitor.

When it is determined that a ground fault has occurred, the image voltage and current detection unit 960 controls the output of various signals that can be visually identified while outputting the corresponding audio-level signal so that it is easily recognized by the surroundings, and also controls the circuit breaker 950 to control DC power. It is natural that the corresponding line of the road can be blocked.

The image voltage current detection unit 960 will be described and understood as having software, hardware, and firmware that perform such functions.

When the DC line ground fault detector 970 is connected between the neutral point and the ground point of the neutral point grounding transformer 930 so that the DC separation power capacitor 971 is interposed, the AC line is connected by DC-AC converter separation (DC Galvanic). While located at, it has the advantage of accurately detecting a ground fault that occurs in a DC converter.

The DC line ground fault detection unit 970 is located in the AC line by DC-AC converter separation (DC Galvanic), and the ground fault current (Ig) due to the occurrence of a ground fault in the DC line is applied to the neutral point grounding transformer 930 to be neutral. There is an advantage of preventing the occurrence of fire and electric shock due to burnout of the grounding transformer 930 or the heat storage of the neutral grounding transformer 930.

FIG. 6 is a configuration diagram of a DC converter ground fault detection device operating system for a photovoltaic power generation system converter integrated neutral point grounding transformer according to an embodiment of the present invention, and FIG. 7 is an access prevention device according to an embodiment of the present invention. It is a detailed configuration diagram.

6 and 7 are mainly described, but referring to all the accompanying drawings, the DC converter ground fault detection device operating system 1000 for the solar power generation system converter integrated neutral point grounding transformer includes the image voltage current detection unit 960 and the system operation. The control unit 1100, the short-range multi-wireless communication module unit 1200, the access prevention device unit 1300, the multi-wireless communication module unit 1400, the smart mobile unit 1500, the multi-public communication network unit 1600, and the integrated management server It is a configuration including the unit 1700.

In the following description, configuring multiple communication paths comprising a plurality of communication paths is intended to block or reduce data transmission errors.

The DC converter ground fault detection device operating system 1000 for the solar power generation system converter integrated neutral point transformer is a video that detects the occurrence of a ground fault in the DC converter of the DC converter ground fault detection device for the solar power generation system converter integrated neutral point transformer. Voltage current detection unit 960; A system operation control unit 1100 that connects to the image voltage and current detection unit 960, controls and monitors the operation of the entire system, and controls and monitors an alarm message to be output when a ground fault occurs in a DC line; Short-distance for simultaneous access to a designated counterpart by activating multiple wireless communication paths of Wi-Fi method, Bluetooth method, and infrared method by the corresponding control signal of the system operation control unit 1100 and transmitting or receiving a communication signal notifying the occurrence of a ground fault. Multiple wireless communication unit 1200; An access prevention device unit 1300 that is installed around a ground fault in response to a corresponding control signal from the system operation control unit 1100 and visually displays a guide message indicating that the ground fault has occurred; A smart mobile unit 1500 for receiving and outputting a communication signal notifying the occurrence of a ground fault and simultaneously wirelessly accessing the short-range multiple wireless communication unit 1200 and multiple wireless communication paths; Includes.

On the other hand, a multi-wireless communication module unit 1400 that transmits the warning message of the occurrence of a ground fault by the corresponding control signal of the system operation control unit 1100 in the same manner through three communication paths according to the CDMA method, the TRS method, and the FM SSB method. ; A multi-public communication network unit 1600 wirelessly connecting to the multi-wireless communication module unit 1400 and transmitting an alarm message signal of an occurrence of a ground fault to a designated counterpart connected by switching; An integrated management server (1700) connecting to the multi-public communication network unit (1600), recording and storing an alarm message signal of a ground fault occurrence in an allocated area, and outputting by searching; It includes more.

Since the configuration and function of the image voltage current detection unit 960 installed in the AC converter to detect a ground fault in the DC converter have already been described in detail, redundant descriptions will be omitted and only necessary parts will be further described.

The system operation control unit 1100 controls and monitors the entire operation of the DC converter ground fault detection device operating system 1000 for a solar power generation system converter integrated neutral point grounding transformer, and outputs corresponding control signals to each configured functional unit. Specific functions of the system operation control unit 1100 will be described again in detail while describing each configuration below.

The short-range multi-wireless communication module unit 1200 includes both a Wi-Fi wireless communication unit 1201, a Bluetooth wireless communication unit 1203, and an infrared wireless communication unit 1205, so that all three types of wireless communication paths can be used, and the system operation control unit 1100 ) By the corresponding control signal at the same time, and simultaneously transmits and receives communication signals with the same contents through three types of wireless communication paths.

The short-range multiplex wireless communication module unit 1200 communicates by wirelessly connecting with the smart mobile unit 1500 according to the corresponding control signal of the system operation control unit 1100, but consists of three types of wireless communication paths including a Wi-Fi method, a Bluetooth method, and an infrared method. Through the wireless communication path of the method, it simultaneously wirelessly connects with the designated counterpart, and transmits the communication signal of the relevant information notifying the occurrence of a ground fault through each route to the designated counterpart at the same time with the same contents, and receives the communication signal. The designated counterpart includes the smart mobile unit 1500.

In the event of a ground fault, one or more of the access prevention device 1300 is installed around an area where there is a high risk of safety accidents such as electric shock or fire, and a warning signal or guidance by the corresponding control signal of the system operation control unit 1100 Display the message visually.

The system operation control unit 1100 records and manages each location information or coordinate information in which a plurality of access prevention unit units 1300 are installed in advance, and each access prevention unit unit 1300 is assigned or assigned a unique number. The operation control unit 1100 may control to display a warning message by operating the selected specific access prevention device unit 1300 while communicating with each access prevention device unit 1300. The system operation control unit 1100 transmits the location information of the operated access prevention device unit 1300 to a designated counterpart or integrated management server in need.

The access prevention device unit 1300 includes an automatic opening and closing door 1301, an access prevention housing 1302, an access prevention communication module unit 1303, a piston rod 1304, a solenoid actuator 1305, and an access prevention message display unit 1306. It is made including.

The automatic opening/closing door 1301 is generally configured in a flat plate state, and is installed on the open upper side of the access prevention housing 1302, and one end of the open upper end of the access prevention housing 1302 is hinged with a spring. It is rotated and opens the open surface of the access prevention housing 1302 but is opened by an external force, and when the external force is removed, it is automatically closed and driven by the elastic force of the spring configured together with the hinge and the weight of the automatic opening and closing door 1301.

A solar cell 1301s is installed on the upper plane constituting the automatic opening/closing door 1301, generating operating power by irradiation of sunlight or sunlight-like light irradiated from the outside, and a built-in charge/discharge battery unit 1301b ) And charged through a charging process, and the operation power charged in this way is supplied to the operation power through a discharging process to the respective functional units of the access prevention device unit 1300. On the other hand, a warning output unit 1301d is installed on the lower plane constituting the automatic opening and closing door 1301, and a message guiding access prevention or a warning message notifying the situation of a dangerous area is displayed by the corresponding control signal, but the message is a still image. It is described and understood that a message and a video message are included, and a corresponding functional unit for displaying a video message is provided in-house.

The access-preventing housing 1302 has the shape of a cylinder or box having a uniform thickness as a whole, and the upper side is open and the other side is a closed shape, but the open upper side is a hinge structure provided with a spring. ) Is connected and installed in a rotating state. The access prevention housing 1302 is shown in the drawing as being buried underground, but may be installed at a specific position on the ground or at a designated position and fixed at a specific height if necessary.

The access prevention communication module unit 1303 is equipped with all three LAN communication functions of the system operation control unit 1100 and the LAN communication method by wired, Wi-Fi, and Bluetooth, and simultaneously activates and operates three communication functions. Simultaneous access by route.

The access prevention communication module unit 1303 connects to the system operation control unit 1100 via a three-way LAN communication path by wired LAN, WiFi LAN, and Bluetooth LAN, and simultaneously transmits and receives various communication signals of the same content. Therefore, it is a configuration that blocks or minimizes transmission errors.

The access prevention communication module unit 1303 has both a wired LAN communication unit (WLC), a Wi-Fi wireless LAN communication unit (WRLC), and a Bluetooth wireless LAN communication unit (BRLC), and simultaneously connects with the system operation control unit 1100 by operating in an active state. , Simultaneous transmission and reception of the same signal and control to select and use the signal of the path with the least transmission error among the signals received through each path according to the analysis of the system operation control unit 1100 and the corresponding control signal, or a signal selected in a specified order Control to use or control to use a commonly known arithmetic mean operation-processed signal. When multiple communication paths consisting of three communication paths are used, transmission errors of data signals can be eliminated or reduced.

The piston rod 1304 is connected to the drive shaft of the solenoid actuator 1305 and is extended by the drive of the solenoid actuator 1305, so it protrudes or compresses to the outside of the access prevention housing 1302 and is inside the access prevention housing 1302. It is a configuration that is reduced to settle.

The solenoid actuator 1305 is fixedly installed in a vertical position at the center of the bottom surface of the access prevention housing 1302, and is received via the access prevention communication module 1303 by the corresponding control signal from the system operation control unit 1100. In operation, a piston rod 1304 is connected to the drive shaft, and the piston rod 1304 is extended to the outside of the access preventing housing 1302 or compressed into the inside of the access preventing housing 1302. The solenoid actuator 1305 receives the operation power applied from the charge/discharge battery unit 1301b as an energy source and drives the drive shaft in an extended or compressed state by a corresponding control signal.

The access prevention message display unit 1306 is installed at the upper end of the piston rod 1304 in a rotating state by a hinge, but when the piston rod 1304 is extended to the outside of the access prevention housing 1302, an automatic opening/closing door 1301 ) And the automatic opening/closing door (1301) is opened by a driving weight (1306w), while the front is rotated to be in a vertical state, so that the message displayed on the front can be easily checked around, and the piston rod (1304) is installed. When it is compressed into the interior of the access prevention housing 1302, it is installed to be driven so that the front of the automatic opening and closing door 1301 is not continuously contacted by rotating in a horizontal direction inside the access prevention housing 1302. It is quite natural that, if necessary, a cam configuration or a similar configuration may be further provided to the rotationally coupled portion of the access prevention message display unit 1306 and the piston rod 1304 in a vertical state and rotate in a horizontal state. The access prevention message display unit 1306 is described and understood as a configuration for outputting a multimedia signal, and further detailed descriptions will be omitted.

The access prevention message display unit 1306 notifies the occurrence of a ground fault by multimedia signals including audio and video signals by the corresponding control signal of the system operation control unit 1100 received via the access prevention communication module unit 1303 A warning message or a guide message is displayed. On the other hand, the system operation control unit 1100 includes coordinate information of the location where the access prevention device unit 1300 operates, output message information, and all the corresponding information including the location and status information of the detected ground fault. 1700).

The multi-wireless communication module unit 1400 is equipped with both a CDMA wireless communication unit 1401, a TRS wireless communication unit 1402, and an FM SSB wireless communication unit 1403 at the same time, and a CDMA method and a CDMA method and a corresponding control signal from the system operation control unit 1100 TRS method and FM SSB method operate in active state at the same time, and each communication path transmits and receives communication data signals of the same content at the same time, and the received communication data signal is the path with the least transmission error. When a signal is selected or the transmission error is the same, a signal of any one path selected in a specified order may be selected, or a signal output by performing a known arithmetic mean operation may be selected. If necessary, any one of these selection methods or any one or more of these may be used simultaneously. The multi-wireless communication module unit 1400 simultaneously accesses the multi-public communication network unit 1600 through three types of communication paths, simultaneously transmits and receives communication signals having the same contents, and blocks or minimizes transmission errors of communication signals.

Since the configuration and operation of CDMA wireless communication, TRS wireless communication, and FM SSB wireless communication are well known, a detailed description will be omitted.

The smart mobile unit 1500 may include a mobile terminal for mobile communication including a smart phone, a data terminal, a dedicated terminal, a notebook computer, a computer, etc., and short-range multi-wireless communication for wireless connection with the short-range multiple wireless communication module unit 1200 A Wi-Fi wireless communication unit 1501, a Bluetooth wireless communication unit 1503, and an infrared wireless communication unit 1505 that respectively connect to the three types of wireless communication paths of the module unit 1200 are provided, and are operated in an active state at the same time. It transmits and receives the same message signal for communication at the same time.

The smart mobile part 1500 is a communication device possessed by an operator, a person in charge, an operator, a related person, etc., located in the vicinity where the short-range multi-wireless communication module unit 1200 is installed and the ground fault has occurred, and may include a plurality of one or more people. The operator, the person in charge, the worker, and the related person can know the location of the ground fault, the accident status, etc., by the corresponding message signal transmitted from the system operation control unit 1100, and can quickly take necessary follow-up measures. An operator, a person in charge, an operator, a related person, etc. are designated counterparts and may refer to one or more of a plurality of smart mobile units 1500.

The multi-public communication network unit 1600 is a public communication network having a switching function and sets a path connected to the integrated management server 1700 by a corresponding control signal from the system operation control unit 1100 to switching. Since the switching configuration and function in the communication network are well known, further detailed description will be omitted. The multi-public communication network unit 1600 is a component that wirelessly connects and communicates with the multi-wireless communication module unit 1400, and an operator or person in charge located at a remote location from the location where the ground fault has occurred by the corresponding control signal of the system operation control unit 1100 , It connects to an operator, a related person, etc. to notify the occurrence of the ground fault, and at the same time, connects to the integrated management server 1700 located in a remote location to transmit all information related to the occurrence of the ground fault. The system operation control unit 1100 transmits, records, and searches all information related to the occurrence of a ground fault to the integrated management server 1700. In the same manner as above, the multi-public communication network unit 1600 blocks transmission errors by the corresponding control signals and monitoring signals of the system operation control unit 1100 or selects a communication signal of a path with fewer transmission errors and is connected to the integrated management server 1700. ) Or to the designated party. The operator and the person in charge, and the workers and related persons, etc., will be referred to as designated counterparts.

The integrated management server 1700 includes large computers and personal computers that are generally classified, and the other party permitted by the network connection and the corresponding program records and manages various information data through remote access and provides the recorded data information by searching. I can. The integrated management server 1700 is operated by the corresponding control and monitoring of the system operation control unit 1100.

The above configuration is simple and inexpensive to detect the occurrence of a ground fault in the DC converter in the AC converter, and generates a warning message or an alarm signal in the vicinity of the ground fault to prevent safety accidents such as electric shock or fire. It quickly and accurately transmits the status information of the occurrence of a ground fault to a designated counterpart located in a short distance or a designated counterpart located at a remote location, and uses multiple communication paths to block or reduce the transmission error of the data signal, and a ground fault to the integrated management server located at a remote location It records and manages all information related to occurrence, and has the advantage of being able to search and utilize it when necessary.

In the above, the present invention has been described in detail with respect to the described specific examples, but it is obvious to those skilled in the art that various modifications and modifications are possible within the scope of the technical idea of the present invention, and it is natural that such modifications and modifications belong to the appended claims.

800: Ground fault detection device using a neutral ground transformer
900: DC converter ground fault detection device for a solar power generation system converter integrated neutral point grounding transformer
810, 910: solar module 820, 920: inverter
830, 930: neutral ground transformer 840, 940: current limiting resistor
850, 950: circuit breaker 860, 960: image voltage and current detector
970: DC circuit ground fault detection unit 1100: System operation control unit
1000: DC converter ground fault detection device operating system for a solar power generation system converter integrated neutral point grounding transformer 1200: Short-range multiplexed wireless communication module unit
1300: access prevention device unit 1400: multiple wireless communication module unit
1500: part of smart mobile 1600: part of multi-public communication network
1700: Integrated management server unit

Claims (4)

delete delete Photovoltaic power generation including a neutral point grounding transformer 930 that receives the AC power output by converting the DC power generated from the solar module 910 into three phases of 60 Hz by the inverter 920 and being inputted to the primary winding 931 In the DC converter ground fault detection device for a system converter integrated neutral point grounding transformer,
Further comprising a DC line ground fault detection unit 970 interposed between the neutral point and the ground point of the primary winding 931 to detect the occurrence of a ground fault in the DC line by detecting the image voltage,
The DC converter ground fault detection unit 970
A capacitor 971 connected in series between the neutral point and the ground point of the primary winding 931;
A first resistor 972 having one end connected to the neutral point of the primary winding 931;
A second resistor 973 having one end connected to the other end of the first resistor 972 and the other end connected to the ground point;
A bridge diode part 974 connecting an input terminal to one end of the second resistor and the other end of the second resistor;
It is connected to the output terminal of the bridge diode unit 974 and detects the level of the video voltage distributed by the second resistor 973. If it is analyzed as a level higher than the set voltage, it is determined that a ground fault has occurred in the DC line and an alarm message is displayed. An image voltage current detection unit 960 for outputting and detecting an occurrence of a ground fault in the DC converter; Including,
A system operation control unit 1100 that connects to the image voltage and current detection unit 960, controls and monitors the operation of the entire system, and controls and monitors an alarm message to be output when a ground fault occurs in a DC line;
Short-distance for simultaneous access to a designated counterpart by activating multiple wireless communication paths of Wi-Fi method, Bluetooth method, and infrared method by the corresponding control signal of the system operation control unit 1100 and transmitting or receiving a communication signal notifying the occurrence of a ground fault. Multiple wireless communication unit 1200;
An access prevention device unit 1300 that is installed around a ground fault in response to a corresponding control signal from the system operation control unit 1100 and visually displays a guide message indicating that the ground fault has occurred;
A smart mobile unit 1500 for receiving and outputting a communication signal notifying the occurrence of a ground fault and simultaneously wirelessly accessing the short-range multiple wireless communication unit 1200 and multiple wireless communication paths; Including,
The access prevention device unit 1300 is
The overall configuration is in a flat plate state, and one end is rotated by being coupled with an open upper end of the access prevention housing 1302 and a hinge provided with a spring, and the open surface of the access prevention housing 1302 is opened by external force, Automatic opening and closing door 1301 that automatically closes by its own weight when the external force is removed;
The automatic opening and closing door 1301 is connected and installed in a rotating state and has a cylindrical box shape having a uniform thickness, the upper side is open, the other side is sealed, but the open upper side is provided with a hinge configuration with a spring. An access prevention housing 1302;
The system operation control unit 1100 and the access prevention communication module unit 1303 are equipped with all three communication function units of wired, Wi-Fi, and LAN communication method by Bluetooth, and are simultaneously activated and operated to simultaneously access three communication paths. ;
A solenoid actuator that is fixedly installed in a vertical state at the center position of the bottom surface of the access prevention housing 1302 and operated by a corresponding control signal from the system operation control unit 1100 received via the access prevention communication module unit 1303 1305);
A piston that is connected to the drive shaft of the solenoid actuator 1305 and is extended by the drive of the solenoid actuator 1305, so that it protrudes or is compressed to the outside of the access prevention housing 1302 and is reduced to seat inside the access prevention housing 1302 Rod 1304;
It is installed at the upper end of the piston rod 1304 in a rotating state by a hinge, but when the piston rod 1304 is extended to the outside of the access prevention housing 1302, it is automatically opened and closed by temporary contact with the automatic opening and closing door 1301 While opening the door 1301, the front is rotated to be in a vertical state by the driving weight (1306w), and access prevention is installed to facilitate confirmation of the message displayed on the front by the corresponding control signal from the system operation control unit (1100). A message display unit 1306; A DC converter ground fault detection device operating system for a photovoltaic power generation system converter-integrated neutral point grounding transformer comprising a.
The method of claim 3,
A multi-wireless communication module unit 1400 for transmitting the warning message of the occurrence of a ground fault according to the corresponding control signal of the system operation control unit 1100 through three communication paths according to a CDMA method, a TRS method, and an FM SSB method;
A multi-public communication network unit 1600 wirelessly connecting to the multi-wireless communication module unit 1400 and transmitting an alarm message signal of an occurrence of a ground fault to a designated counterpart connected by switching;
An integrated management server (1700) connecting to the multi-public communication network unit (1600), recording and storing an alarm message signal of a ground fault occurrence in an allocated area, and outputting by searching; Including more,
The condenser 971 is made of 92 microwaves,
The first resistor 972 is made of 50 kilohms,
The second resistor 973 is made of 5 kiohms,
The first resistor 972 and the second resistor 973 are connected in series and connected to the capacitor 971 in parallel.A direct current circuit ground fault detection device operating system for a converter-integrated neutral point transformer.

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